Serious attempts to build thinking machines began after the second world war. One line of research, called Cybernetics, used electronic circuitry imitating nervous systems to make machines that learned to recognize simple patterns, and turtle-like robots that found their way to recharging plugs. A different approach, named Artificial Intelligence, harnessed the arithmetic power of post-war computers to abstract reasoning, and by the 1960s made computers prove theorems in logic and geometry, solve calculus problems and play good games of checkers. At the end of the 1960s, research groups at MIT and Stanford attached television cameras and robot arms to their computers, so "thinking" programs could begin to collect information directly from the real world.